CM

BMS175: Topic 2: The Renal System

Part 1: The Renal System - Anatomy and Urine Formation

List and Identify the organs of the renal system

  • Kidneys

  • Ureters

  • Urinary Bladder

  • Urethra

Define the functions of the renal system

  • Kidneys produce urine as a way to remove any unwanted and unneeded waste products from the body

  • Kidneys have a large role in regulating the concentration of multiple ions in blood

  • Kidneys also help to maintain blood osmolarity

  • Kidneys can regulate blood pressure and blood glucose levels

Describe the location and position of the kidneys

  • Located on the posterior abdominal wall on either side of the vertebral column

  • The right kidney is slightly lower

Define Nephron

  • “Nephrons are the functional units of the kidney”

  • Kidneys contain about 1 million nephrons that simultaneously make urine each

How many processes are involved in the formation of urine

  • Three processes

    • Glomerular filtration

    • Tubular reabsorption

    • Tubular secretion

Define nitrogenous waste

  • Nucleic acids and proteins that have nitrogen in them

  • Then the body’s cells break down molecules that contain nitrogen we end with nitrogen, carbon and hydrogen

  • The body uses the coat on and oxygen but gets rid of nitrogen as it forms ammonia

  • The most abundant nitrogenous waste is urea

Explain the process of glomerular filtration (Process 1)

  • Blood enters and returns out of the glomerular capsule (the blood vessels that are inside the capsule have holes in them)

  • As the blood is moving in and out some molecules in the blood drop inside the capsule

  • Molecules in the blood such as water, glucose, ions and nitrogenous pass from the blood to the nephron

  • Larger structures such as erythrocytes cannot enter the nephron

Explain the process of tubular reabsorption (Process 2)

  • The nutrients such as glucose and acids are reclaimed back into the bloodstream

  • Water and ions are also reclaimed as needed

Explain the process of tubular secretion (Process 3)

  • This process passes certain substances from the blood to the nephron

  • These substances can include selected drugs, hormones and urea

Part 2: The Renal System - Urine Formation, Regulation and Excretion

Explain how the kidneys regulate urine concentration and volume

  • Kidneys respond to ones intake and loss of fluids

  • They make adjustments to keep the solute concentration of the body’s fluids normal and consistent

  • Kidneys do this by regulating concentration and volume

  • When dehydrated - kidneys produce a small amount of concentrated urine

  • When overhydrated - kidneys produce a large amount of dilute urine

Describe the flow of urine from the nephron to ureter

  • The path urine moves through to end up at the ureter

  • Structures called calyces > renal pelvis > finally to the ureter

Describe the function of the ureters

  • Thin tubes that moves/transport urine from the kidneys to the bladder

Identify the location of the female bladder and urethra

  • Located anterior to vagina and uterus

Identify the location of the male bladder and urethra

  • Prostate gland lies inferior to the bladder neck, which empties into the urethra